1. Field of the Invention
This invention relates to couplers for trailers. More specifically, this invention relates to ball-type couplers for goose neck and fifth wheel trailers which permit the positioning of the ball within the coupler while the trailer is positioned at an angle relative to the towing vehicle and which improves and simplifies the attachment between a towing vehicle having a ball hitch and a trailer having the hitch coupler of this invention. Still more specifically, this invention relates to ball hitch couplers having a single rotatable locking element for holding the ball hitch within the coupler of this invention.
2. Description of the Related Art
A variety of ball-type couplers are well known in the art to connect a towing vehicle to a trailer. A common arrangement is a generally spherical housing which is open along a bottom portion and a rear portion. The ball is positioned within the housing by sliding it upwardly through the open bottom and to a position in which the ball rests against the inside of the housing. A lever or other similar latching element which is disposed in the open rear portion is moved into a position adjacent to the ball, to thereby prevent withdrawal of the ball through the opening in the bottom. This is achieved by the lever or other latching element being moved into the area adjacent to the lower curvature of the ball. By locking the latching element in place, the ball is kept within the housing. Often such couplers requires several locking surfaces for locking the ball to the coupler, thereby complicating the coupler mechanism, decreasing its reliability, and increasing its manufacturing cost. Other coupler approaches include devices employing multiple pivotally connected control elements; sidewise dampening or braking elements; height adjustment mechanisms; U-shaped tongue hitch devices; removable hitch features; draw bars; a socket adapted for placement on the roof of the towing vehicle; a gooseneck hitch coupler; fifth-wheel hitch couplers; a shock absorbing bumper; a collar coupler, a shock absorbing trailer hitch for cushioning end thrust shocks; non-ball high clearance vehicle hitch; truck bed ball hitch assembly; up and down adjustable ball hitches; a mounting bracket for attachment to the rear bumper of a pickup truck; a plurality of ball-socket hitch couplers; a convertible hitch device which is readily adapted for attachment to the rear bumper plate of commonly used towing vehicles; a tongue for connecting the towing vehicle to the trailer; a latching assembly using manually operable gears; elongated truck trailer tongue assemblies; a trailer hitch carriage; multiple ball locking elements; trailer connecting running gear; towing system designed for use with tubular rear bumpers; hitch bar couplers; multiple links connected to ball joints; slidable locking mechanisms; elastomerized shear cushioning; hitch adapters for use with double caster wheel trailers; a coupling structure not utilizing ball and socket coupling; combined receiver trailer hitch and bumper assemblies; a three point hitch assembly; a three point coupling device; accessory mounting apparatuses; hitch having an axially extending pin for fixing the hitch; a self aligning hitch device; power operated hitch mechanisms; trailer uncoupler devices; folding ball hitch devices; and a collar for trailer hitch receivers. Each such embodiment or application has the important disadvantages of being mechanically complex both to install and to manufacture. Simplified ball couplers which provide increased strength and decreased manufacturing costs permit the ball coupler to find greater application in solving towing problems.
For general background material, the reader is directed to U.S. Pat. Nos. 3,600,004, 3,633,939, 3,655,221, 3,703,301, 3,716,255, 3,741,587, 3,756,624, 3,796,444, 3,797,685, 3,811,706, 3,837,675, 3,840,252, 3,843,161, 3,863,956, 3,900,212, 3,972,541, 3,990,722, 4,046,398, 4,088,339, 4,103,928, 4,119,328, 4,157,189, 4,168,082, 4,192,524, 4,220,350, 4,227,713, 4,240,647, 4,253,679, 4,256,323, 4,272,098, 4,361,939, 4,365,820, 4,398,743, 4,402,523, 4,420,169, 4,426,097, 4,438,944, 4,443,025, 4,560,184, 4,606,549, 4,613,149, 4,626,154, 4,664,403, 4,699,395, 4,714,264, 4,721,323, 4,738,464, 4,792,151, 4,811,967, 4,921,266, 4,940,096, 4,944,354, 4,950,010, 4,955,631, 4,968,053, 4,991,864, 5,016,898, 5,058,915, 5,085,451, 5,110,024, 5,110,149, 5,161,815, 5,167,423, 5,259,223, 5,328,198, 5,332,248, 5,344,173, 5,378,007, 5,387,002, 5,435,585, 5,435,586, 5,472,222, 5,501,481, 5,503,421, 5,509,682, 5,516,137, 5,531,560, 5,575,491, 5,609,350 and 5,620,198, each of which is hereby incorporated by reference in its entirety for the material disclosed therein.